Colloquia & Guest Speakers
Interfacial Exciton Control for Solar Energy Conversion and Optoelectronics
YunHui (Lisa) Lin, Director's Postdoctoral Fellow, National Renewable Energy Laboratory
Wednesday, October 4, 2023
Presented in-person in Goergen 101 and on Zoom
Meeting ID: 952 7674 7247
The ability to manage energy and charge flow at interfaces is central to the function of many optical, electronic, and spintronic systems. A subset of these technologies relies on the properties of triplet excitons, taking advantage of their long lifetimes, statistical abundance, or unique spin interactions. In this talk, I will discuss how photoinduced triplet generation or charge separation enables new functionality in both photovoltaic (light harvesting) and luminescent (light emitting) systems. First, I will present our work on organic photovoltaics using cooperative exciton effects involving triplets (namely, singlet fission and triplet triplet annihilation upconversion), which can bring device performance beyond conventional efficiency limits. Next, I will introduce low-dimensional hybrid organic-inorganic perovskites as platforms for some unique nanoscale light-matter interactions and triplet photochemistry. In particular, I will present recent understanding of how several perovskite design parameters, including the interfacial energy level alignment and organic layer morphology, affect ultrafast energy transfer dynamics and final luminescence outcomes. Ultimately, a better understanding of and control over interfacial exciton dynamics in these unique semiconductors will accelerate the discovery of new materials with valuable optical and electronic applications, including broadband color-tunable emitters, more efficient LEDs and solar cells, and flexible electronics.
YunHui (Lisa) Lin completed her bachelor and doctorate degrees in electrical engineering and materials science at Princeton University. In 2018, she was a hardware engineering intern in the Display Investigations team at Apple. After earning her PhD in 2019, Lisa received a Director’s Fellowship to conduct postdoctoral research at the National Renewable Energy Laboratory. She is interested in low-dimensional hybrid perovskites as platforms for unique nanoscale light-matter interactions, ultrafast phenomena at hybrid organic/inorganic interfaces, and the design of novel semiconductors for energy conversion and optoelectronics.